Cathead



Sept. 14, 1948. O. M. GJAHAGAN 2,449,376

GATHEAD Filed March 25, 1945 I 2 Sheets-Sheetl flTTOR/VEYS.

S p 14, 1948- o. M. GAHAGAN' 2,449,376

r V CATHEAD Filed March 25, 1945 2 Sheets-Sheet 2 a INVENTOR.

1 O/Y'en/V. fiaka a/r 65 22 m 5 FY W 4 3? 37 ATTORNE ya Patented Sept. 14, 1948 UNITED S TAT ES OFFI C E CATHEAD Orren Gahagan, ,l)allas, .T ex.

Application March 23, 194'5,*'Serial No; 584341 "This invention relates *to a device commonly known as a cathead for operating the jerk line employed in setting up andbreaking the tool joints of drill pipe, couplings of casing, and similar threaded connectionsencountered in well drilling operations.

The principal objects of the invention are to 'provide a device of this character of sturdy, light weight, compact construction capable of .withstanding shock incidental to application 'of power applied to the jerk line and the resultant recoil incidental to breaking loose of a threaded joint.

ot-her objects of the invention are to provide such device with a resilient mounting fortakin'g up shocks ordinarily absorbed"by the equipment on which the device is mounted; toprovide a cathead which includes a driving member adapted for rigid mounting "on "shaft of a "draw Works and having a bearing portion journaled within a control housing that encloses the jerk line sheave and on which the sheave is rotatably and slidably mounted for engagement'withthe driving member; to provide a simple-sheave shift and control mechanism; to provide an arrangement of i clutch lugs between the jerkline sheave and driving member forobtaining the desired operating interval between the time the jerk line sheave is shifted to drivenposition and-application of rotating power thereto by -thedriving member; to provide sheave throw'out, 'checkyaQnd rest ele- -ments cooperation with oneof the clutch lugs on the jerk line sheave; 'to provide a jerk line sheave having an annular shiftingrim thereon formed as a continuation of one sidefiange of the jerk linesheave; to provide a throw out element on the control housing shaped forfac'ilitati-ng the disengagement of'the clutch lugs; to provide "a :single'shift lever forthe jerk line sheave that may be located in any position circumferentially f the control housing on whichit is mounted; and to provide a simple latchmechanism for retaining the jerk line sheave in engaged and disengaged positions.

Another object 'of the invention is to provide a simple: andsecureconnection of the jerk line with :the jerk line sheave and 'wh ic'h is readily connected and removed therefrom.

It is also: a further object of the invention' to provide a: cathea d-"spool havin-gshape 'for' resist- :in'g wear of a catlinesithereon iandiitozprovide space --forx accommodating 'Ithei driving clutchi lugs L inset rwithina the body nfrthetspool which: results inria more compact arid light weight construction. iIniaccomplishingthese and tether mbjects of the invention hereinafter point-ed outtfixhavezprov'ide'd improved structure;thepreferred forms of 'which are illustrated in the accompanying drawings yvherein 1 r Fig. 1 is a side elevational (view of :a cathea'd constructed in accordance :with the present invention, parts being shown in' section to zbette illustrateparts enclosed thereby.

'Fig. '2 is a vertical section through the cathead "showing the -jerk line sheave 1 in iposition :to .be

engagedby the driving member. 1 r

Fig. 3 is a similar'view showingrth e tjerkreline sheave out .of drivin xposition.

Fig. 4 is; a, fragmentary section througha por- 1 3 'tion of the 1 control housing and the mounting therefor, particularly illustrating the sheave disengaging, :check, .and rest elements in relation withtheropening throughwhich'the :ierk line is ithreaded onto the ierk line sheave.

cat-head shown in disassembled :spaced relation to 'ibetteriillustrate the construction thereof.

:Fig. 16' is "a 'cross section through the cathea'd xon theil-ine 6-:56' of Fig.3.

:FigJT-is'a fragmentary sectionall vieiw particurlaizlyiillustrating"the latch for retaining the jerk "lines-sheave in engaged and disengaged positions :thereof.

iFig. 8sis a a ifragmentary sectioni through. a de- 730 :vice sconstructed inv accordance with l the present 'invention an'd which includes a modified form'of catline spool that resultsin a shorter over-all length-and provides a stronger structure;

Referring more in detail to the drawings:

.l designates a tdevice 1 commonly known as *a cathead adapted to: be applied to theline shaft :2 ofcaidrawworks of .a-drilling rig, and which is used in operatin cthe jerk-line 3 in combination with wrenches or tongs for making up and breakvi-ng joints of casinggwtool joints 0f drill'pipe, and

conventional catli-ne (notshovvn) is adapted to be wound incidental to certain drilling operations. The outer side of :the cathead terminates v .in an annular flange Hi to retain the catline thereonaand-.thevopposite or base side connects .:-Fig w5 is.aeperspective-tview :of the parts of the rotation of the driven member therein.

shock absorbing pad 35.

best shown in Fig. 6.

by a disk-like web portion or annulus II with a hub I2. The hub I2 has an axial bore I3 whereby the cathead is mounted on the line shaft 3 and connected therewith through a key I4 inserted within a way I5 of the line shaft and a registering way I6 of the hub I2 as shown in Figs. 2 and 3. If desired, the web portion I I may be inset within the base portion of the cathead as indicated at I1 (Fig. 8) for a purpose to be later described. Formecl on the outer face of the web II and projecting therefrom are one or more lugs I8 shown on the drawings as two in number and diametrically arranged with respect to each other. The lugs I8 have driving faces I9 arranged in the forward direction of rotation of the cathead and adapted to engage complementary lugs 20 on the jerk line sheave 6 later described. The rear faces of the lugs I8 are sloped as at It to shift the sheave for carrying the lugs 2 out of the path of the lugs I8, should the rotation of the drive shaft be reversed.

The control housing 5 includes a hub or sleeve portion 2I sleeved over the hub or bearing portion I2 of the driving member and which cooperates therewith in mounting an anti-friction bearing 22 preferably including a circumferential series of rollers. The anti-friction bearing reduces torque on the control housing and provides free The housing 5 also includes a web portion 24 extending circumferentially of the sleeve portion 2| at one end thereof and which carries a lateral circumferential flange 25 preferably of a width to overlapthe web portion I I of the driving member 'to form an annular chamber 26 for housing the jerk line sheave 6.

The housing 5 is anchored to a fixed part of the draw works;for example, an adjacent jackpost 21 thereof by bracket 28 having a leg or plate portion 29 adapted to be secured to the jackpost by fastening devices such as bolts 30 that extend through suitable openings 3 I Extending laterally from the leg :29 is an arm 32 positioned between spaced ears 33 and 34 on'the flange of the housing and which cooperate with the arm to embrace a The shock absorbing pad is preferably of channel shape to provide a web portion 36 engaged between the flange of the housing and the upper face of the arm 32 and flange portions 31 engaged between the ears 33 and 34 and the respective sides of the arm as If desired, a fastening devicesuch as a bolt 38 may be passed through opening 39 in the ears and registering opening 49 of the arm of the bracket to retain the shock absorbing pad and cooperate with the hub portion I2 of the'driven member in maintaining a substantially fixed position for the control housing.

The jerk line sheave 6 includes a ring-like body 4I having an inner diameter to be freely and slidably rotatable on the sleeve portion 2| of the control housing 5 and having suitable width and thickness for accommodating a groove 42 part way therearound and in which the jerk line 3 is adapted'to operate as later described, the dimensions of the sheave being such as to'limit the mass of the sheave to that necessary in accommodating the line groove and providing the necessary strength so as to reduce the inertia thereof when disengaged from the driving member as later described. The groove 42 provides side flanges 43 and 44 on the respective sides of the sheave and one of the flanges, for example, the flange 43 is extended radially to provide an annular shaft lever engaging portion or rim 45 so as face of the flange 44 as in'dicated at 41 to engage a throwout element 48 and a check and rest element 49. The length of the sleeve portion 2| is such that when the jerk line sheave is positioned adjacent the web portion 24 of the housing the lugs 26 on the sheave are clear of the lugs I9 on the driven member. The jerk line sheave, therefore, has two positions relatively to the longitudinal axis of the sleeve 2I, that is, engaged and disengaged positions, which positions are maintained by a latch 50, best shown in Fig. '1. The latch 59 comprises a spring leaf 5I having one end anchored to the exterior face of the flange 25 by fastening devices such as screws 52. The other or free end of the leaf terminates in a substantially V-shaped latch head 53 that operates through an opening 54 in the flange of the control housing and has converging sides 55 and 56, (Fig. '1) to engage the respective sides of the rim portion 45 of the sheave flange 43. In order to manually shift the jerk line sheave from the disengaged position shown in Figs. 3 and '7 to driven position, a lever 51 is pivotally mounted on a pin 58 carried by ears 59 and 60 located at any convenient point about the circumference of the control housing. The lever 51 has a sub stantially fork-shaped head 6I that projects through a slot-62 in the control housing at a point intermediate the cars 59 and 60 and straddles the rim portion 45 of the flange 43 as clearly shown in Figs. 1, 2, and 3. The outer end of the lever may be connected in any suitable manner with a hand or foot control (not shown) located conveniently for the driller.-

In order to provide a readily detachable connection of the jerk line 3 with the sheave, one end of the jerk line carriesa knob 63 suitably fixed thereto and which engages in a socket 64 in the periphery of the sheave near one of the lugs 20. The other end'of the groove 42 is also connected with the socket through a bore 65.

To facilitate threading of the jerk line in the sheave, the flange of the control housing has an opening 66 in a side thereof of sufiicient size to freely pass the knob 63 when the socket 64 is registered therewith. When the socket 64 of the sheave is registered with the opening 66, it is obvious that the free end of the jerk line or that to be attached to the tong, is readily passed through the opening 66, socket 64, and bore 65 to lie within the groove of the sheave. After passing into the groove, the free end of the line is drawn through an opening 61 of the flange to seat the knob 63 in the socket 64.

In order that the entire circumference of the sheave may be utilized in applying power to the jerk line and to provide a maximum stroke therefor, the check and rest 49 is located intermediate the openings 66 and 61, as shown in Figs. 5 and 6. The check and rest element 49 is formed by a lug preferably integral with the control housing and which is shaped to provide a check face 68 facing theopening 61 and a rest face 69 facing the opening 66, which faces are adapted to be engaged by the projecting portion 41 of the lug 20.

The throw'out element 48 is also preferably integral with the flange and includes a substantially wedge-shaped lughaving one side located parallel with the-web H, and one side tapering toward the-web"2-4 for shifting of the pulley out of driven position whentheextension- 47i en- H gages therewith. Upon'release of drivingengagement, the sheave is free-to rotate to its original position under recoil of the jerk line or by a pull on the jerk line when the operator backs up the tongs, in which position the lug extension 41 -rests against the restface 69 of the lug .49.

In order to retain thecontrol housingin proper position on the bearing portion of the hub I2 of "the driving member, the hub lz has an annular grocveli in the end-thereof adjacentthejackpost 2-! to receive an inwardly extending rib-12 on a ring 13. The ring is preferably-formed in sections 14 and 15 (Fig. 5) adapted to be placed separately in the groove H of'thehub l2 and secured in position by fastening devices 16 extended through registering ears 1! on the ends of the respective sections as best shown in Figs. land 5. The ring also includes an outwardly extending flange portion! spaced from the outer face of the web portion'm of the control housing to accommodate a. spacer ring 19 therebetween. The roller bearing surfaces, including the bearing surface of the sheave and sleeve of the control housing, are supplied with lubricant through a duct 80 extending within thecathead portion of .9

the driving member and having one end threaded into a-port 8! registeringwith the roller bearing as shownin Figs. 2 and. 3. The opposite end of the duct is suitably attached to the outer end =of the cathead-and carries a pressure fitting 82. ."li he space occupied by the roller bearing is connected with .the bearing face --of the sheave tthrOllg-h ports 83so that lubricant from the bearing space passes therethrough.

In assembling an apparatus constructed as described, the roller bearing 22 may be applied within the sleeve portion 2! of the control housing 5 or to the hub portion !2 of the driving member. The jerk line sheave 6 is then passed over the sleeve portion 2! so that it enters the annular space 26. The shift lever 51 may then be applied so that the forked end 6| thereof engages over the rim 45 of the sheave. The control housing containing the sheave is sleeved upon the hub portion ll of the driving member 4 and is followed by the spacer ring 19. The sections 14 and 75 of the retaining ring 13 are then applied so that the ribs 12 thereon engage in the annular groove ii of the hub I 2 and are secured by passing the fastening devices 16 through the ear portions Tl thereof to complete the assembly of the unit.

In assembling the unit on a line shaft 2 of a draw works, the key =14 is removed from the way i5 and the hub portion l 2 of the driving member 4 is sleeved on the projecting end of the shaft 2 so that the way 16 thereof registers with the way ill in the line shaft. The key M is then driven into position to retain the assembly. The arm 2 of the bracket 28 is inserted in position between the ears 3 and 34 and retained by the fastening device 38. The plate portion 29 of the bracket 28 is then secured to the jackpost 2'! by the fastening devices 30. The sheave 6 is positioned within the control housing 5 so that the lug having the end 41 engages the rest face 69 of the stop lug 49 in which position the socket 64 registers with the opening 66 and the bore 65 substantially aligns with the opening 61. The end of the jerk line 3 which is to be attached to the "inimpartinga pull on the jerk line.

:tongs may: then be threaded through the opencontrol adj acent 'the drillers position.

Whemadrawworksiis in operation, the shaft l2 is-rotatingthe memberA; however, when the sheave B-is indisengaged position shown in-Fig. r3, f'the lugs 'IB on the driving member will pass the lugs 2llon-thesheave'6. The sheave is retained in -this position bythe latch head 53 engaging zthe rim s of the sheave flange 43.

'Y'Zhe parts are shown'in their normalat rest uposition win F-Figsj 3 and=6 with the lug 20 on the ssh-cave resting against the rest "facectil of the stoptilugds. "Any slackinthe jerk line is drawn v:upuponapplication of the tongs so that-when rafjoint is to hehrokcn or tightened, -power-of theadriving meinber i is immediately effective This is-effected ibyishiftin-g the lever t l-to movethe jerk llitllGrShGZ-LVC biz-imposition as shownin Figs. land ulsothatvthelugsstil thereon are in position to be engaged by thepplaneting lugs.- lihonrxthe driving member 4. The sheave B is retainedxinf thisrposixtion by the latch head =53; engaging the opposite side of the rim 45 of? the sheave fiangei43. Upon engagement of the lugsti8 of the driving member with the lugsw20 on the sheave 6, the sheave at is rotated in a counter-clockwise direction (Fig. 6) to effect wrapping of .thejerklineabout the periphery on the sheave. Thesudden application of power applied: to theline effects a snap ontthe line ,suiiicientto crack or tighten the joint as the casermayi be. The sheavevfi continues its rotation until the extension lug 41 engages the face N1 of the throw out element 48 after which rotation of the sheave is checked by the extension 4'! of the sheave striking the check face 68. After disengagement, the sheave is kept free of the lugs !8 since it is re-engaged by the side of the latch 50. The sheave is now free to return to its normal or resting position incidental to recoil in the jerk line or back up of the tongs.

With the form of spool shown in Fig. 8, the inset web at the base of the spool locates the lugs l8 within the limits of the spool and results in a shorter over-all length and a lighter weight unit.

From the foregoing it is obvious that I have provided a cathead of sturdy, light weight, and compact construction providing ample stroke necessary in cracking or tightening a joint and which is capable of providing lasting and satisfactory service.

What I claim and desire to secure by Letters Patent is:

1. A device of the character described including a driving member having a bearing portion and an annulus at one end of the bearing portion, sheave control means carried on the bear ing portion of the driving member, a sheave rotatable about the bearing portion and slidable to and from the annulus, interengaging means on said annulus and sheave, means carried on the control means for sliding the sheave to effect engagement of said interengaging means, throw out means on the control means engageable with a part on the sheave to effect disengagement of said interengaging means after a predetermined rotation of the sheave by said driving member, a jerk line having one end anchored to the sheave for winding about the sheave when the sheave is rotated by the driving member and to effect reverse rotation of the sheave after disengagement of the interengaging means, stop means on the control means for limitingthe extent of rotation of the sheaveabout said bearing portion, a bracket for supporting the sheave control means, spaced ears on the sheave control means for receiving a portion of said bracket therebetween, and resilient means between said portion of the bracket and said ears for absorbing shocks resulting from engagement of said part on the sheave with said stop means.

2. In an apparatus of the character described, a support, a shaft rotatable n the support, a driving member on the shaft having a bearing portion, a sheave control means mounted on the bearing portion of the driving member, a driven member rotatable about said bearing portion, means selectively connecting the driven member with the driving member, means for efiecting automatic disengagement of said members, means for mounting the control means on the support including a bracket, a channel-like resilient member straddling the bracket, spaced ears on the control means engaging the resilient member, and a fastening device extending through said ears and bracket.

3. A device of the character described including a driving member having a bearing portion extending coaxial ly from a side thereof, a sheave control housing carried on the bearing portion, a sheave rotatable about the bearing portion and slidable axially thereof, said sheave having an annular flange at one side of a line groove in said sheave, means extending laterally from the driving member and sheave on facing sides thereof and adapted to interengage when the sheave is shifted laterally from an idle position toward the driving member to effect interengagement of .said laterally extending means, a lever having a forked end engaging the annular flange, means for pivotally mounting the lever on the control housing to effect said shift of the sheave, throwout means on the control housing engageable with the means on the sheave to effect disengagement of said laterally extending means after a predetermied rotation of the sheave by the driving member and to effect return of said sheave to idle position, a jerk line having one end anchored to the sheave for winding about the sheave when the sheave is rotated by the driving member and to effect reverse rotation of the sheave upon disengagement of said laterally extending means, stop means on the control housing for limiting the extent of reverse rotation of the sheave about said bearing portion, and a latch carried by the control housing and engaging over said flange to retain the sheave in said idle position during any turning of the sheave incidental to manipulation of the jerk line prior to release of said latch from engagement with said flange.

ORAREN M. GAHAGAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 18,789 Gahagan Apr. 4, 1933 1,629,662 Hill et a1. May 24, 1927 1,755,728 Foster Apr. 22, 1930 2,124,129 Therolf July 19, 1938 2,138,175 Keys Nov. 29, 1938 2,314,733 O'wen Mar. 23, 1943 

